Mahaim fibers

Jump to navigation Jump to search

WikiDoc Resources for Mahaim fibers

Articles

Most recent articles on Mahaim fibers

Most cited articles on Mahaim fibers

Review articles on Mahaim fibers

Articles on Mahaim fibers in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Mahaim fibers

Images of Mahaim fibers

Photos of Mahaim fibers

Podcasts & MP3s on Mahaim fibers

Videos on Mahaim fibers

Evidence Based Medicine

Cochrane Collaboration on Mahaim fibers

Bandolier on Mahaim fibers

TRIP on Mahaim fibers

Clinical Trials

Ongoing Trials on Mahaim fibers at Clinical Trials.gov

Trial results on Mahaim fibers

Clinical Trials on Mahaim fibers at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Mahaim fibers

NICE Guidance on Mahaim fibers

NHS PRODIGY Guidance

FDA on Mahaim fibers

CDC on Mahaim fibers

Books

Books on Mahaim fibers

News

Mahaim fibers in the news

Be alerted to news on Mahaim fibers

News trends on Mahaim fibers

Commentary

Blogs on Mahaim fibers

Definitions

Definitions of Mahaim fibers

Patient Resources / Community

Patient resources on Mahaim fibers

Discussion groups on Mahaim fibers

Patient Handouts on Mahaim fibers

Directions to Hospitals Treating Mahaim fibers

Risk calculators and risk factors for Mahaim fibers

Healthcare Provider Resources

Symptoms of Mahaim fibers

Causes & Risk Factors for Mahaim fibers

Diagnostic studies for Mahaim fibers

Treatment of Mahaim fibers

Continuing Medical Education (CME)

CME Programs on Mahaim fibers

International

Mahaim fibers en Espanol

Mahaim fibers en Francais

Business

Mahaim fibers in the Marketplace

Patents on Mahaim fibers

Experimental / Informatics

List of terms related to Mahaim fibers

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Vendhan Ramanujam M.B.B.S [2]

Synonyms and keywords: Atypical bypass tracts, fasciculoventricular fibers, Mahaim physiology, nodoventricular fibers, paraspecific fibers of Mahaim

Overview

Mahaim fibers refer to the connecting fibers originating from the atrioventricular node (AV node), bundle of His, or left bundle branch that join the ventricular myocardium. The myocardial fibers resemble the tissue of origin and gradually take over the characteristics of the ventricular myocardial cells.[1] Mahaim fibers may be present from the AV node to the right, left, or middle part of the interventricular septum. They may serve as the substrate for a variety of pre-excitation syndromes.

Historical Perspective

Mahaim and Benatt described the islands of conducting tissue extending from the bundle of His to the ventricular myocardium in 1937.[2] These fasciculoventricular fibers as well as the nodofascicular fibers are referred to as Mahaim fibers. However, Gillette and his colleagues provided evidences suggesting anatomic substrates of the preexciation variants previously attributed to Mahaim fibers may be actually atriofascicular or atrioventricular pathways that possess anterograde decremental conduction properties.[3]

Pathophysiology

There are two varieties of Mahaim fibers namely nodoventricular and fasciculoventricular connections. Nodoventricular accessory connections connect AV node to ventricular myocardium and fasciculoventricular connections connect bundle of His (distal part of junctional area) to ventricular myocardium. Both mediate the atrioventricular bypass through the normal conducting system. These accesory pathways lack the rate-slowing property of AV node. So a rapid conduction through there fibers will lead to short PR interval and reentrant tachycardia.

Conditions Involving Mahaim Fibers

Mahaim tachycardia is a reentrant tachycardia that occurs using the Mahaim fibers as antegrade limb and AV node as retrograde limb.[4]

Treatment

  • Mahaim tachycardia is sensitive to adenosine but not to other agents that predominately affect the AV node. However, AV nodal blocking agents like calcium channel blockers and beta blockers may be effective in preventing tachycardia by affecting the retrograde AV nodal conduction in the retrograde limb of tachycardia. Both class of IA and IC antiarrhythmic agents may also slow Mahaim fiber tachycardia.
  • Catheter ablation of the atrioventricular junction may be useful for treating recurrent tachycardia in patients with Mahaim fibers.

References

  1. A. John Camm MD FRCP FESC FACC FAHA FHRS; Sanjeev Saksena MBBS MD FACC FESC FHRS FAHA (2011). Electrophysiological Disorders of the Heart: Expert Consult - Online and Print, 2e. Philadelphia: Saunders. ISBN 1-4377-0285-6.
  2. Mahaim, Ivan; Benatt, Alfred (1937). "Nouvelles recherches sur les connexions supérieures de la branche gauche du faisceau de His-Tawara avec la cloison interventriculaire". Cardiology. 1 (2): 61–73. doi:10.1159/000164567. ISSN 1421-9751.
  3. Gillette PC, Garson A, Cooley DA, McNamara DG (1982). "Prolonged and decremental antegrade conduction properties in right anterior accessory connections: Wide QRS antidromic tachycardia of left bundle branch block pattern without Wolff-Parkinson-White configuration in sinus rhythm". American Heart Journal. 103 (1): 66–74. PMID 7055047. Unknown parameter |month= ignored (help)
  4. Tchou P, Lehmann MH, Jazayeri M, Akhtar M (1988). "Atriofascicular connection or a nodoventricular Mahaim fiber? Electrophysiologic elucidation of the pathway and associated reentrant circuit". Circulation. 77 (4): 837–48. PMID 3127077. Unknown parameter |month= ignored (help)

See also


Template:WikiDoc Sources